The objective is to develop the applicant's skills in behavioral genetics research and augment her training in the electrophysiology and developmental neuropsychology of ADHD. Given the strong influence that genes have on brain development, the integration of genetics and measures of brain activity is a logical one that may lead to increased understanding of the etiology and neurophysiology of ADHD. This study proposes to take a step in that direction by investigating the association between genetic markers and quantitative traits such as electrophysiological measures of brain function, neuropsychological deficits, and behavior ratings from parents and teachers. Specifically, this project proposes to examine genetic variations that identify functional arid clinical differences among subtypes of children with ADHD. The long-term goal of this project is to understand the neural mechanism through which genetic polymorphisms produce the cognitive and behavioral phenotypes evident among children with ADHD. The applicant's strong background of clinical training and research in neurocognitive development and EEG measurement among children with ADHD provides an excellent foundation for this work. The Career Development Plan will develop the PI's skills in: 1) the design of studies that collect human genetic material; 2) data analytic methods used to examine genetic associations with other sources of data (i.e., electrophysiological data); and 3) Interpretation of genetic associations. Methods of career development include: 1) the proposed study; 2) the mentorship of Drs. Susan Smally, Andrew Leuchter, and Nelson Freimer; 3) consultation with experts in population, behavioral, and statistical genetics; 4) formal coursework; 5) attendance at scientific meetings; and 6) data preparation for submission to professionally refereed journals. Given the applicant's prior training, proposed mentorship, and outstanding resources, a K23 Award will enable her to become an independent and productive researcher in the genetics and developmental neuropsychology of ADHD.